Bump kotlin version to 1.4.0-rc

Author: erokhins

gradle.properties

@@ -3,13 +3,13 @@
 #
 
 # Kotlin
-version=1.3.8-1.4.0-rc-218
+version=1.3.8-1.4.0-rc
 group=org.jetbrains.kotlinx
-kotlin_version=1.4.0-rc-218
+kotlin_version=1.4.0-rc
 
 # Dependencies
 junit_version=4.12
-atomicfu_version=0.14.3-1.4.0-rc-218
+atomicfu_version=0.14.3-1.4.0-rc
 knit_version=0.1.3
 html_version=0.6.8
 lincheck_version=2.7.1